Improvement in operating valves of steam-engines



v `'LIMITED STATES PATENTI OFFICE.

II. UHRY AND II. A. LUTTGENS, OF PATERSON, NEW JERSEY.

IMPROVEMENT IN OPERATING VALVES OF STEAM-ENGINES.

Specification forming part of Letters Patent No. 21,455, dated September 7, 1858.

` of the shaft.VV The key is pressed by a spiral j T0 all whom it may concern:

Be it`- known that we, II. UHRY and II. A. LUTTGENS, of the city of Paterson, in the county of Passaic and State of New Jersey, have invented a new and Improved Mode of Operating the Valves of Steam-Engines; and We do hereby declare that the following is a full and exact description thereof, reference being had to the accompanyingdrawings, and to the letters of reference marked thereon.

Figure VIII is a section and end elevation showing the eccentrics and the mechanism applied for moving the valve-rod. Fig. IX is a front elevation; Fig. X, a plan ot' the same; Fig. XI, an elevation of a modification of the same motion. Fig.XlI is a separate end elevation of the rockers as connected with the ordinary link; Fig. XIII, a front elevation of the latter; Figs. XIV and XV, elevation and section of the cam drawn separately.

The saine letters of reference refer to the same parts in all the figures.

The nature of our invention consists in operating 'a single slide-valve by one cam and two eccentrics, which are connected to a link and differential rocker.

The eccentric-rods are connected to the npper and lower partof a slotted arc called the link, which is held in its position and vi brates upon a hanger supported by the end of a reversing-lever. The link is provided with a sliding block which is connected by a pin to a differential rocker or to alever of the first or third degree, as occasion may require, having its 'fulcrum in the center of the above-named sliding block and operating either the valverod directly or connecting with the latter through the intervention of a common rocker, as now commonly used on locomotive-engines, the extremity of the dif-` ferential rocker being operated by a cam-rod and the cam arranged upon the shaft with the eccentrics operating the link. It is found necessary for the proper adjustment of the forward motion to set the center line of the crank some iifteen degrees (more orless) in advance of the center line of the cam, a circumstance, however, which does not favor the back motion, which defect is overcome by making the cam to fit loose upon the shaft, its key fitting into a broad key-seat, wider than the keyitself, cut into the circumference spring which is adjusted by a set-screw tting into the hub of the cam.` The back motion becomes suiiciently correct if the cam falls back in the reverse or back motion, so that its center line lies in one plane with the center line of the crank.

To enable others skilled in the art to make and use our invention, we will proceed to describe its construction and operation.

A represents the main axle or shaft of an engine.

S is the crank fitted and keyed upon the end of the shaft.

B4 is a cam with three corners constructed to fill the yoke B5, which latter has facings of steel plates as wide as the cam itself and is connected top-and bottom by screw-bolts, the upper one of which is supported by a hanger supported and secured to some part of the framing of the engine, allowing it to vibrate horizontally without materially changing its vertical-position.

D and C are the forward and back eccentrics, which, with the cam B4, are fitted and secured to the shaft. The cam is either permanently fixed by a set-screw d6 or a keyf, or the key-seat upon the shaft is lengthened. `as shown at f6, Fig. XIV, the key being pressed by the spiral spring e6 and set-screw d6. The center line ofthe crank in the direction of motion of the engine is set some fifteen degrees (more or less) in advance of the center line of the cam, and after the cam is fixed the lead of the valve is adjusted by the eccentrics without changing the position ofthe cam.

The ends of the eccentric-rods R and Q are connected to the link b v pins, and the cam-rod P3 is connected in the same manner to the lower end of the differential rocker G. of which in this case the central joint m' is formed in connection with the lower arm of the rocker O, being secured together by a pin, While the upper arm of the differential rocker G is provided with a pin carrying the block g, which fits into and slides within the link E.

The lower arm of rocker O is slotted, as shown at c, to give room for the vibrations of the bolt and nut m2, securing the pin holding the block g to the extremity of the differential rocker G. If the latter should form a lever of the first degree, the slot within the rocker O may be dispensed withl and the lowerrocker-arm made of the same shapeas the upper arm. To the saddle c of the link E is secured by a pin the hanger e, the lower end f of which is carried by the reversing-le- 'cured to the engine-frame, and its upper end connects by a pin to the Valve-rod end' p;

The modification as represented in Fig. Xl

dispenses with the rocker O, andthe motion is communicated directly to the valve-rod p.

, The connection m4 between the link and valve*- rod is fitted on one end by a pinto the block g of the link E, and at the other end-it is connected in the same manner to the valve-rod p, while it is itself supported bya hanger m3, the upper end of which is connected-.bya pin to some part of the framing of the engine. The pins and bearings of rockers are fitted to turn freely.

The operation is as follows: AS with the common link-motion, the two eccentrics C D give motion to the extremities of the link E in opposite directions, only that lthe eccentricsare not set upon the shaft in'advanceto Vthe amount of the entire lap and lead, as the cam provides for this requisite. Themotionthus produced by the link in its diierentpositions as adj usted by the hanger @reversingo-` ted by the diiferen'tial rocker G, the lower'end of'which is moved by the cam-rod P3. Thus the combined motion of the link E and carnrod l?3 operates either the valve-rod@ directly, as shown in Fig. XI, or one end of alever or rocker O, which communicatesmotion to the valve through Valve-rod 19. When the Valve is worked with its largest throw, the block g; being adjusted so as to work near the ends of" the link E, the cam B4 affects theval-ve motionin a manner so as to decrease its throw; but when the link E is raised or lowered so as to bring the block g nearer to the center of the `link E, the same as with the common link,

decreasing the motion of the valve, the eect of the cam motion is to increase the throw of thevalve, which latter in that case acquires more fully in its movements the peculiarities ot" the cam motio'm thus giving at the higher grades of expansion, as compared `with the thev common link-motion, (both valve-gears givingthe same amount of motion at their largest throw and an equal amount of cut-off lat that point,) an average of neara double i openingV of the steam-port, a later opening of thel communication of the steam-passage with the exhaust-port, and a consiflerable-decrease of preadmission of lead. Vthere a larger f opening of thesteamport is desir-able,itl may [beobtaifned by sl'otti-ng the lo'weren'd ot the differenti-alrocker G and7 providing; it with@ a block, the same as the link. It is operatedby the endof the cam-rod P3. I't rein-ainsrtlren by a mod-e of adjustment the same as that of the link E to raisey the endzof the ca1nrod' P3, While the block gr within thex liinkE iszlbweerl' orraised towardy its center, and ag'aifnrto-lower the, former, While the block. g With-iin theel-ink E is brought near the ends of thelatte'r.

In the usual practicewhere the; si-idewaljve is unbalancedit is` toundl of advantage-to` pil-'ovide the end of the ,clife-l-'ential rocker, in

stead of Witha slot,.with several holes by leith'er ot which the pin securing the end? ot' thecamfrod P3 may beheld, thus-givi'ngpower of adjustment while the engine is at rest only.. levers H K, and reversing-rod M is transmit- 'V-Vedo not claiml the connection ot th-.edi'fferential rocker G with the l-i-n'k-motionj or Egl'e slide-valve, substantially as described.

H. UHRY. [n s-.]s H. A.' LUT'EGENS. [n s.]. Witnesses:

' J @HN E. MANsoN,

GEORGE BEEsLEY. 

